You haven't provided enough information to make an ID. A photo would be a huge help. Failing that, we need a description of length, girth, ground color, pattern, ventral color/pattern, etc. Then MAYBE we can offer an educated guess based on description and locale.
By the way, if it wasn't a Rattlesnake, it didn't have a button. If it did have a button, then it was a rattlesnake. There is no other genus in North America that has buttons or rattles. The only other snake I can think of that has a similar tail adaptation is the Bushmaster from Central and South America, and that's not really rattles, but more a series of scales that form small spines on the tail. Lot's of harmless snakes will rattle their tails when alarmed presumeably to try to convince their attacker that they are a rattlesnake. In dry leaves, it can make a somewhat similar sound.